function pageScroll() {
  $("#backtop").css("background-position-x", "-28px"),
      window.scrollBy(0, -20),
      scrolldelay = setTimeout("pageScroll()", 2),
  0 == document.documentElement.scrollTop && 0 == document.body.scrollTop && ($("#backtop").css("background-position-x", "0"), clearTimeout(scrolldelay))
}
function cloud_animate(a, b) {
  $("#" + a).animate({
        marginLeft: parseInt($("#" + a).css("marginLeft")) + 30 * b
      },
      cloud_time,
      function() {
        cloud_animate(a, -b)
      })
}
export {
  pageScroll,
  cloud_animate
}